function i=getIFromMassA_gedian(mass01,mass02,seperation)
M1min=2;
M1max=150;
M1step=1;

amax=10000;amin=3;
ccstep=0.01;

qmin=0.08;
qmax=1;
qstep=0.1;

q=mass02/mass01;
Imass01=round((mass01-M1min)./(M1step));

Iq=round((q-qmin)./qstep);

cc=(log(seperation)-log(amin))./(log(amax)-log(amin));
Ia=round(cc./ccstep);


qNum=ceil((qmax-qmin)./qstep);
mass01Num=ceil((M1max-M1min)./M1step);
% ccNum=ceil((log(amax)-log(amin))./(log(amax)-log(amin))./ccstep);
ccNum=101;
i = Ia + Iq * ccNum + Imass01 * qNum * ccNum + 1;
end